Can anyone explain the XCR's operating system?How does it compare to the SIG 556? or Colt gas piston upper?I am familiar with the AR-15 system and acquainted with a gas piston system.Please educate me.

I've never read it, so I cannot tell you if there's info on the gas system or not.

Boy, the next word that comes out of your mouth had better be some brilliant f**kin' Mark Twain sh**, 'cause it's definitely gettin' chiselled on your tombstone.Otis B. Driftwood in The Devil's Rejects